Pneumatic tool.



C. CHHISTIANSEN.

v PNEUMATIC TOOL. APPLICATION FILED JULY 21. 1915.

Patented Oct. 26, 1915.

CHARLES CHRISTIANSEN, 0F GELSENJKIRGEEIN, GER.

PNEUMATIC TOOL.

To all whom it may concern:

Be it known that I, CHARLES GHRISTIAN SEN, a citizen of the German Empire, residing at Gelsenkirchen, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in Pneumatic Tools, of which the following is a specification.

My invention relates to pneumatic (compressed air) tools of the kind which are fitted with a separate controlling member for the admission of the compressed air and a separate controlling member for the exhaust, which controlling members are both operated and reversed by the drop in pressure and the compression, respectively, alternately produced in the operative cylinder, together with the action of the fresh air. In such tools auxiliary exhaust passageshave been hitherto provided, which were disposed at a distance from the ends of the cylinder A section through a tool according to the pres-- ent invention. Fig 2 illustrates another constructional form of the controlling members of such a tool.

In Fig. 1 a is the cylinder'in which reciprocates the piston 72. c is the main exhaust port. The controlling member, (Z is here shown in form of a flap, but which may also have the form of a ball, a lens, a plate or the like, not shown; e and f are the admission passages. g is the exhaust controlling member and h the auxiliary exhaust leading into the atmosphere. The cylindrical controlling member g consists of a hollow body, having small bores t" at either end adapted to alternately form a communication between the cavity within the said hollow body 9 and the passages f or a, re-

spectively, according to the position of said controlling member. The cavity in said controlling member further communicates with the auxiliary exhaust h by means of a bore 7c Specification of Letters Patent.

Application filed. July 21, 1915. I Serial 110. 41,199.

Patented Met. 2%, 113115.

intermediate the ends of said body. 'At the terminal positions of said member 9 the ends of the latter project into the passages f or g,

respectively, but without completely closing the same, so that fresh air may pass around she end of the said member 9- into the cyliner a.

At the position of the parts shown in Fig. 1 fresh air will enter below the left wing of the flap d and will thereupon flow through the passage e into the cylinder at. In consequence thereof the piston 12 will be driven to the, right. The air in front of the piston escapes via 7, i, is and. it into the atmosphere. In the drawing the parts are shown in their positions at the moment when the piston b is just clearing the main exhaust port 0. This causes a sudden drop in the pressure behind the piston b. This drop of pressure in combination with the slight com pression in front of the piston b is suficient to reverse the flap valve (Z in a known manner. Immediately thereafter also the exhaust member 9' is. reversed, because the pressure on its left end drops and a pressure is exerted on its right end by the fresh air entering through passage f.

In the modification shown in Fig. 2 the flap d controls the admission of the fresh air through the admission passages e and f, respectively as in Fig. 1, the auxiliary exhaust port It is controlled by an exhaust controlling member 9 which here is made in form of a flap valve. The continuations c and f of the passages e and 7, respectively, conduct the fresh air to the cylinder, while the short passages h and 72, form the communication with the auxiliary exhaust port 71.. The operation is essentially the same as with the embodiment described hereinbefore to said ports, an air admission controlling V member, and an exhaust controlling member operable by a difierence in pressure on their opposite ends to alternately connect the adiio mission port and exhaust port with oppo site ends of the cylinder.

2. pneumatic tool comprising a cylinder having an exhaust port therein, a piston in the cylinder, an air admission port and an auxiliary exhaust port communicating with the cylinder at its ends by passages common to said admission and auxiliary ports, a valve controlling the admission port, and a valve controlling the auxiliary exhaust port, both of said valves being operable by a difference of pressure on their opposite endsto alternately connect the admission port and auxiliary port'with opposite ends of the cylinder.

3. A pneumatic tool comprising a cylinder having an exhaust port therein, a piston in the cylinder controlling said port, an air admission port and an auxiliary exhaust port communicating with the cylinder at its ends by passages common to said admission and auxiliary ports, separate valves control lingthe admission port and auxiliary exauxiliary port with opposite ends of the cylinder.

4. A pneumatic tool comprising a cylinder having an exhaust port therein, a piston in the cylinder controlling said port, an air admission port, passages connecting the latter with opposite ends of the cylinder, a. valve to alternately close the inlet ends of said passages, an auxiliary exhaust port arranged to communicate with the cylinder through said passages, and a valve to connect the auxiliary exhaust with said passages alternately, said valves operable by a reduction of pressure and by compression in the cylinder to connect the air admission port with one end of the cylinder and to connect the auxiliary exhaust with the opposite end of the cylinder.

In witness whereof I have hereunto set my hand in presence of two witnesses.

CHARLES CHRISTIANSEN. Witnesses:

FRIDA KLAIBER, PAULINE MiiLLnR. 

